Disease relevance of apaH

• Escherichia coli strains with abnormally high concentrations of bis(5'-nucleosidyl)-tetraphosphates (Ap4N) were constructed by disrupting the apaH gene that encodes Ap4N-hydrolase [1].
• The ygdP and apaH genes of Salmonella enterica serovar Typhimurium (S. Typhimurium) encode two unrelated dinucleoside polyphosphate (NpnN) hydrolases [2].

High impact information on apaH

• An apaH mutation causes AppppA to accumulate and affects motility and catabolite repression in Escherichia coli [3].
• The normal level of 3 microM adenylated NpnN (ApnN) was increased 1.5-, 3.5-, and 10-fold in the ygdP, apaH and double mutants, respectively [2].
• The were not sensitive to kasugamycin, the apaH- apaG- ksgA- strain filamented and stopped growing in the presence of this antibiotic at 600 micrograms/ml [1].
• The growth inhibition was abolished upon complementation with a plasmid carrying an intact apaH gene [1].
• CfcA11 has a mutation in glySa which encodes the alpha-subunit of glycyl-tRNA synthetase, and cfcB1 has an IS2 insertion in apaH which encodes Ap4A hydrolase [4].

Biological context of apaH

• Previously, Blanchin-Roland et al. showed that ksgA and apaH form a complex operon (Mol. Gen. Genet. 205:515-522, 1986) [5].
• This promoter, active in vivo, can account for p1-independent expression of the two distal cistrons, apaG and apaH [6].
• The DNA sequences of the diadenosine tetraphosphatase gene (apaH) and of the flanking regions were determined [6].
• The other open reading frame was located counterclockwise to the apaH-like gene [7].

Anatomical context of apaH

• Disruption of ygdP, apaH individually, and disruption of both genes together reduced intracellular invasion of human HEp-2 epithelial cells by S [2].

References